Query Param Parser
Parse URLs and raw query strings into decoded key and value pairs and rebuild them cleanly.
What is Query Param Parser?
Inspect a URL's query string and distinguish missing, empty and repeated values. Query parameters describe an ordered set of name/value pairs; a plain object can lose repeated keys.
How to use Query Param Parser?
Step 1
Paste a full URL or raw query string.
Step 2
Review the decoded table of parameters.
Step 3
Edit values if needed and copy the rebuilt query string.
Example input / output
In ?tag=api&tag=java&empty=&q=C%2B%2B, tag occurs twice, empty is present with an empty value, and q decodes to C++. A bare plus in a form-encoded query decodes to a space.
Example input
https://example.com/callback?redirect=%2Ftools%2Fjwt-decoder&team=platform&team=qaCheck the result
- Repeated keys can appear multiple times and should be preserved intentionally.
- Encoded JSON values may need additional decoding after parameter parsing.
Practical developer examples
Retain repeated parameters
Use all occurrences when checking filters or API clients. A server may interpret repeated keys differently from a comma-separated value.
Separate fragments
The #fragment belongs to the client-side URL fragment. It is not part of the HTTP query sent to a server.
Common developer use cases
Parsing does not validate an endpoint's allowed parameters, signatures or business rules. Credentials can appear in a query; redact before sharing.
Common issues
FAQ
Is ?flag the same as no flag?
No. It contains a present flag with an empty value. The endpoint decides how to interpret that.
Does the parser contact the URL?
No. It inspects the string locally without issuing a request.